# PEPPOL-EN16931-R003-SG

Source: https://xmlvalid.com/rules/PEPPOL-EN16931-R003-SG

> A buyer reference or purchase order reference MUST be provided.

- Level: error
- Rule sets: PINT SG rules (Singapore) 1.4.1
- Context: `/ubl:Invoice | /cn:CreditNote`
- Test: `cbc:BuyerReference or cac:OrderReference/cbc:ID`

Validate a document against these rules: https://xmlvalid.com/validate